Squeezing plate mold capable of refining and uniformizing grains for smart phone

Abstract

The invention relates to the technical field of plate extrusion dies, in particular to a plate extrusion die capable of refining and uniformizing grains for smart phones, which comprises a die body, the die body is composed of a guide plate, a die and a correction plate, the die is clamped on one side of the guide plate, and the correction plate is clamped on one side of the die away from the guide plate. The center of the guide plate, the center of the die and the center of the correction plate are each provided with a die hole, the three die holes are designed in an arc shape and communicate with one another to form a penetrating flow channel, the flow channel of metal can be lengthened through the design of the guide plate, sufficient deformation of the metal is facilitated, and more importantly, according to the metal extrusion principle, the flow channel is lengthened, and therefore the machining efficiency is improved. By means of the method, the influence of the turbulent flow state generated when metal in an extrusion container enters a die on metal entering a die hole can be eliminated, grains of a plate produced through the method are fine and uniform, the length of a transverse welding seam of the plate produced through the method is greatly reduced and is within 5% of that of a traditional method, and therefore the yield is greatly increased, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of extruded plate dies, and in particular to an extruded plate die for a smart phone capable of refining and uniforming crystal grains. Background Art

[0002] With the rapid development and progress of science and technology and the continuous improvement of people's living standards and quality, mobile phones have become an indispensable tool in people's lives. Mobile phones have evolved from the single communication function in the past to today's multifunctional intelligent era. Mobile phones integrate information storage, computing, perception, business transactions and communications, and are people's personal core tools and equipment. When choosing a mobile phone, people will not only consider the brand, price and configuration of the mobile phone, but also pay more attention to the material of the mobile phone and pay more and more attention to the sensory characteristics of the mobile phone.

[0003] The material is an important factor that affects the appearance and feel of mobile phones. Aluminum alloy is light, corrosion-resistant, has good formability and is easy to process. It has good thermal conductivity, high specific strength, and very good metal texture. It can be processed into a high-end, beautiful appearance. At the same time, through anodizing and electrolytic coloring, it can achieve a variety of luxurious, bright, and elegant colors, making the appearance of mobile phones colorful. Therefore, aluminum alloy has become the first choice and mainstream material for smart phones. However, based on the appearance and texture of mobile phones and consumers' requirements for quality, aluminum alloy as a mobile phone material has quite high requirements, which is mainly reflected in the surface state and uniformity of the aluminum alloy extruded sheet.

[0004] In particular, the uniformity of the organization has a decisive influence on the texture and color of the subsequent mobile phone surface. This is because as a metal material, the internal grain size will affect the conductivity and mechanical properties of the material. In particular, the unevenness of the grains will lead to the anisotropy of the conductivity of various parts of the material. Aluminum alloys must undergo surface treatments such as anodizing and coloring to become consumer products, and these surface treatments must be completed under current scenarios.

[0005] Therefore, the influence of organizational uniformity on the surface texture and color of mobile phones has aroused great concern among the vast number of engineering and technical personnel in the aluminum extrusion industry. The surface state and organizational uniformity of aluminum alloy mobile phone plates are closely related to factors such as the alloy composition, extrusion process and mold. At present, companies are more troubled by the problems of extrusion molding technology and molds. The problem of molds is more complicated. The mold structure is extremely sensitive to the surface state, organizational uniformity and yield rate of extruded plates.

[0006] Traditional extrusion sheet die has a long weld seam, which is defined by the industry as a long transverse weld seam, resulting in low yield and high cost. At the same time, the die structure is unreasonable, resulting in product deformation and uneven flow rate, which ultimately makes the product grains coarse and uneven. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides an extruded sheet die for smart phones that can refine and uniform the grains, which can effectively solve the problems raised in the background technology.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] The present invention provides an extruded plate die for a smart phone capable of refining and uniforming crystal grains, comprising a die main body, wherein the die main body is composed of a guide plate, a mold and a correction plate, the guide plate is clamped with the mold on one side, and the correction plate is clamped with the side of the mold away from the guide plate, and the guide plate, the mold and the correction plate are all provided with die holes in the centers, the three die holes are all of arc-shaped design, and the three holes are connected to form a through flow channel.

[0010] Furthermore, the inlet profile of the guide plate is enlarged by 10 to 12 mm based on the mold hole profile, and the outlet profile is enlarged by 13 to 15 mm based on the mold hole profile; the depth H of the outlet cavity is 15 to 20 mm, and the upper limit value is taken when the wall thickness of the plate is greater than 8 mm.

[0011] Furthermore, the flow channel of the guide plate is designed to be reverse stepped.

[0012] Furthermore, the entrance of the correction plate is an arc hole, and the outline design principle thereof is: enlarged by 3mm on one side of the die hole.

[0013] Furthermore, the inlet and outlet of the correction plate are in a shape similar to the cross section of the plate, and the deformation angle β of the correction plate is in the range of 65° to 70°.

[0014] Compared with the known prior art, the technical solution provided by the present invention has the following beneficial effects:

[0015] 1. The grains of the plate produced by the present invention are small and uniform;

[0016] 2. The length of the transverse weld of the plate produced by the present invention is greatly reduced, which is within 5% of the traditional one, thereby greatly improving the yield and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1It is a schematic diagram of the cross-sectional dimensions of a conventional extruded sheet;

[0019] Figure 2 It is a schematic diagram of the traditional die hole arrangement;

[0020] Figure 3 It is a schematic diagram of the traditional mold structure;

[0021] Figure 4 This is a schematic diagram of the improved concentric circle die hole arrangement;

[0022] Figure 5 This is a schematic diagram of the improved mold structure;

[0023] Figure 6 This is the structure diagram of the guide plate;

[0024] Figure 7 This is the structural diagram of the correction plate;

[0025] Figure 8 Schematic diagram of cantilever formed by die hole curvature;

[0026] Fig. 9 Schematic diagram of die hole process design.

[0027] The numbers in the figure represent:

[0028] 1. Guide plate; 2. Mold; 3. Correction plate. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention will be further described below in conjunction with the embodiments.

[0031] Embodiment 1:

[0032] Reference Figure 1-4 , which is the first embodiment of the present invention, discloses a typical cross-section of an extruded plate of a smart phone.

[0033] In the figure, L is the length of the cross section of the plate, and t is the thickness of the plate.

[0034] In response to the technical problems described in the background, this case invents a new type of extrusion die structure, which is a concentric circle die hole extrusion die.

[0035] like Figure 2The figure shows the traditional die hole arrangement. In this arrangement, the die hole is in the shape of a "one" and is located on the center line of the die. The die structure is usually a two-piece flat die structure of "die + die pad", such as Figure 3 shown.

[0036] Since extrusion molding is formed by extruding a round bar through an extrusion cylinder with a round inner hole into a mold, this extrusion method has a pressure gradient in the radial direction of the extrusion cylinder, that is, the pressure gradually decreases from the center to the edge, which causes the molding pressure from the center to the edge to be uneven and different when extruding the profile, which easily leads to differences in the metal extrusion flow rate from the center to the edge during the extrusion process. This is the main reason for the extrusion transverse weld, and the transverse weld is manifested as uneven grains and tissues in various sections of the profile in the length direction. That is to say, from the front end to the tail end in length, the coarse grains at the front end gradually transition to the fine grains at the tail end; and in the cross section, the coarse grains in the center gradually transition to the fine grains far away from the center. This is because the tissue of the aluminum bar material is manifested as a surface fine grain area, a columnar grain area and a central equiaxed grain area from the outer layer to the center.

[0037] Embodiment 2:

[0038] In view of the defects of the traditional mold, the present invention designs a concentric die hole extrusion die, that is, the die hole of the profile is designed with a certain curvature, and its center coincides with the mold, so that each part of the die hole is equal to the center of the mold, that is, the entire die hole is on a circumference, such as Figure 4 shown.

[0039] Reference Figure 5-9 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that the above arrangement can make all parts of the die hole in the same pressure field and temperature field, and the extrusion flow rate of each part tends to be consistent, so that the molding stress state of each part is exactly the same, which eliminates the pressure difference between various parts or points of the die hole during extrusion, so that the grain size of each part can be completely consistent.

[0040] On the other hand, such die hole arrangement makes the die hole a certain distance away from the center. Compared with the traditional structure, the maximum edge of the die hole is increased, which is equivalent to increasing the degree of extrusion deformation. The increase in the degree of extrusion deformation will refine the grain of the profile. Since the die hole has a curvature, a correction plate must be added to the die. When the profile is extruded through the die hole, it is still in a high temperature state and has good plasticity. When passing through the correction plate, the cross section gradually changes from an arc shape to a straight line. The improved die structure is as follows Figure 5 shown.

[0041] During the extrusion process, each aluminum rod must be trimmed after extrusion. In the traditional mold structure, when the trim is separated from the mold downward, it will drive the plate in the mold hole to move forward or pull backward, causing the profile between the two aluminum rods to crack at the joint, and also allow air to enter the flow channel. When the second aluminum rod is extruded after the trim is separated, the air in the flow channel will explode under the high temperature and high pressure extrusion conditions, affecting the surface quality of the plate. Therefore, the mold is designed as a three-piece structure of "guide plate 1 + mold 2 + correction plate 3";

[0042] The guide plate 1 is designed to increase the flow channel of the metal, which is beneficial to the full deformation of the metal. More importantly, according to the metal extrusion principle, the increase of the flow channel can eliminate the influence of the turbulent state of the metal in the extrusion barrel entering the die on the metal entering the die hole, which is beneficial to more stable forming of the metal in the die hole; the flow channel of the guide plate 1 is designed to be a reverse step-type or a countersunk hole type, which can prevent the profile between the two aluminum bars from cracking at the joint and air from entering the die hole;

[0043] At the same time, before the metal enters the die hole, this countersunk feed port can form a side pressure, because when the metal enters this part, it first fills the countersunk material cavity and exerts a force on the side wall. Similarly, the side wall also exerts a reaction force on the metal, causing the metal to enter the die hole. Therefore, the metal can be made denser, which is beneficial to the refinement of grains. The structure of the guide plate 1 is as follows Figure 6 shown.

[0044] The structural parameters of the guide plate mainly include the shape and size of the metal inlet and outlet, as well as the depth H of the countersunk type outlet cavity. The inlet contour is enlarged by 10 to 12 mm based on the mold hole contour, and the outlet contour is enlarged by 13 to 15 mm based on the mold hole contour. The depth H of the outlet cavity is 15 to 20 mm, and the upper limit value is taken when the wall thickness of the plate is greater than 8 mm.

[0045] Since the improved die hole is arc-shaped, that is, the extruded profile is not a straight plate, it must be straightened and shaped to achieve a plate that meets the flatness requirements. Since the extrusion is carried out in the range of 480℃~520℃, the temperature of the profile at the moment of separation from the die after extrusion will exceed 520℃. At this time, the material has good plasticity, so a correction plate 3 is set behind the die 2. It is easy to shape using the residual heat of extrusion. The correction plate 3 is very convenient to use taper CNC electric spark wire cutting. The correction plate 3 is as follows Figure 7 shown.

[0046] The relevant parameters of the correction plate 3 are as follows:

[0047] (1) The entrance is an arc hole, and its contour design principle is: enlarge one side of the die hole by 3mm.

[0048] (2)h1 takes (0.5~0.65)h2.

[0049] (3) The outlet has a shape similar to the cross section of the plate, with a length of 1.1L and a width of 1.01t; where L is the width of the plate cross section and t is the thickness or wall thickness of the plate cross section.

[0050] (4) The deformation angle β is in the range of 65° to 70°.

[0051] In order to ensure the flatness of the plate during the calibration process, the curvature of the die hole cannot be too small. If the curvature is too small, it will increase the difficulty of calibration and turn the die 2 into a cantilever beam with a large pressure area. Figure 8 shown.

[0052] When the pressure area of ​​the cantilever beam formed is large, the strength of the mold will be reduced. At the same time, the mold will undergo elastic deflection during extrusion, resulting in uneven wall thickness of the sheet.

[0053] The process design of the die hole is as follows: Fig. 9 shown.

[0054] The relevant parameters are determined as follows:

[0055] D is the inner diameter of the extrusion cylinder (mm), R0 is the radius of the center layer of the die hole, and the relationship between the two is:

[0056] The arc length of the center layer of the die hole should be Where L is the width of the plate section (mm);

[0057] The central angle α is in the range of 120° to 140°;

[0058] The wall thickness δ of the die hole is taken as 1.01t, and the manufacturing deviation is taken as negative difference -0.03 (mm), where t is the thickness or wall thickness of the plate section.

[0059] The remaining structures are the same as those of Example 1.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A die for extruded sheet materials for smart phones capable of making grains fine and uniform, characterized in that: The mold body comprises a guide plate (1), a mold (2) and a correction plate (3); A mold (2) is clamped on one side of the guide plate (1), and a correction plate (3) is clamped on the side of the mold (2) away from the guide plate (1). The guide plate (1), the mold (2) and the correction plate (3) are all provided with mold holes at their centers, and the three mold holes are all arc-shaped in design. The three holes are connected to form a through-flow channel.

2. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The inlet profile of the guide plate (1) is enlarged by 10 to 12 mm based on the die hole profile, and the outlet profile is enlarged by 13 to 15 mm based on the die hole profile; the depth H of the outlet cavity is 15 to 20 mm, and the upper limit value is taken when the wall thickness of the plate is greater than 8 mm.

3. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The flow channel of the guide plate (1) is designed to be in a reverse stepped manner.

4. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The entrance of the correction plate (3) is a circular arc hole, and its contour design principle is: it is formed by enlarging one side of the die hole by 3mm.

5. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The inlet and outlet of the correction plate (3) are in a shape similar to the cross section of the plate, and the deformation angle β of the correction plate (3) is in the range of 65° to 70°.

6. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The arc length of the center layer of the die hole should be Wherein L is the width dimension of the plate section, and the die hole center angle α is in the range of 120° to 140°.

7. The extrusion plate die for smart phones capable of achieving grain refinement and uniformity according to claim 1, characterized in that: The wall thickness δ of the die hole is 1.01t, and the manufacturing deviation is a negative difference of -0.03 (mm), where t is the thickness or wall thickness of the plate section.

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